Managing an Invasive Species While Simultaneously Conserving Native Plant Diversity

Abstract

Management for invasive species is usually done with the intent of maintaining or enhancing one or several ecosystem services. On rangeland landscapes, management is often focused on provisioning services (e.g., livestock) but can also include maintaining biodiversity. Rangeland landscapes are often large and complex, suggesting understanding the invasion and management efforts is best done at multiple scales. The objective of this study was to assess the effectiveness of sericea lespedeza (Lespedeza cuneata [Dum.-Cours] G. Don) management practices on two study areas that were focused on managing livestock and promoting biodiversity simultaneously. At one study area, an experiment containing 134 different prescribed fires was evaluated for 19 yrs comparing pyric herbivory with traditional rangeland management with fire and grazing on sericea lespedeza invasion. The second area had a 21-yr observational study across 16 000 ha with 541 different prescribed burns and on the effects of pyric herbivory and herbicide applications on sericea lespedeza. We found support that pyric herbivory with cattle (Bos spp.) or bison (Bos bison) contributed to long-term invasion mitigation for sericea lespedeza, whereas we found no support that other management practices added to the mitigation provided by pyric herbivory. We found no support for a season of fire effect and/or herbicide control. These practices only provided short-term sericea management (1 yr). Pyric herbivory remains the only viable management action that can reduce the rate of invasion and use this invasive forage legume for livestock production at actual management scales. This study demonstrates the importance of developing large-scale studies of realistic treatments that integrate practices such as fire, grazing, and herbicides to understand the effects of invasion and control efforts on rangelands with multiple objectives.